Accumulators



Oct. 2, 1956 T. J. MOCUISTION ACCUMULATORS Filed Oct. 22, 1953 fie. 1

- INVENTOR. 76mm) IA/cannon BY Irma/vs ys Patented Oct. 2, 1956 UnitedStates Patent Office a mum IACCUMULATORS Tommy J. McCuistion, Euclid,Ohio Application October 22, 1953, Serial No. 387,653

Claims. (Cl. 138-31) This invention relates to the art of accumulatorsof the piston type.

As stated in my co-pending applications, in the use of a piston type ofaccumulator in connection with hydraulic equipment, as for'instance inan airplane, the piercing of the wall of the storage chamber for the oilor other liquid might cause sufiicient increase in internal pressure toproduce an explosionike bursting of the accumulator walls and aconsequent scattering of the metal particles. This of course might proveto be very serious and hence this type of accumulator is a real hazardunder such conditions. 'This old type of accumulator is. objectionablealso becauseof the transmissionof vibrations or surging due to theoperation of the pump connected to the same. s

Accordingly, one object of my present invention is to devise a pistontype of accumulator with means for quickly absorbing increased internalpressure due to, displacement by a bullet or other object piercing thewall and enteringthe liquid-storage chamber of the accumulator.

Another object is to devise an accumulator of this type that is capableof absorbing minor fluctuations or surges of internal pressure thatmight be due to impulses of the pump or other hydraulic" mechanismassociated therewith.

Another object is to devise an accumulator of this type t in which themain piston itself is provided with an auxiliary piston or plunger thatis directly exposed to the pressure within the liquid-containing chamberof the accumulator and that is at once responsive thereto in such manneras to relieve the same at least to a partial extent so as to supplementthe effect of the main piston in together relieving entirely any suchexcessive pressure.

The present disclosure contains certain specific details of constructionwhich are to be considered as forming part of my present invention. andas constituting one of the objects thereof.

Other objects will appear from the following description and claims whenconsidered together with the accompanying drawing.

Fig. 1 is a longitudinal sectional view of a device embodying my presentinvention; and

Fig. 2 is a view taken on line 2-2 of Fig. 1.

It is tobe understood that the present form of disclosure is merely forthe purpose of illustration and that there might 'be variousmodifications without departing from the spirit of my invention asherein set forth and claimed.

Referring now :to the accompanying drawing in detail,

' 2b 01' in any other suitable manner. Likewise any suitable 'i ment ofthe piston towards the right, as viewed in Fig. 1

of the accompanying drawing. v

The nozzle 2a may be closed by the screw form of plug provided with aninwardly peened-over annular flange 5 is adapted for the storage ofoil,'for instance, while the 7 gas-filled chamber 6 is adapted to absorbany excessive pressure within the liquid-containing chamber 5 by move-3b for engagement by the apertured disk 7 which is held thereagainst bythe coil spring 8. The other end of the spring 8 has bearing engagementagainst the disk 9 which has closing engagement against the inner end ofthe screw-threaded open plug 10 in the nozzle 3a. When pressure isapplied inwardly against the disk 9, either by the entering gas or bymeans of a suitable tool through the open plug 10, the gas may .besupplied to the chamber 6 or discharged therefrom. Upon relief of thepressure upon the disk 9, the same will be closed by the spring 8 andheld in such closed position so as toprevent accidental escape of thegas from the chamber 6.

The piston 4 is of substantially I-form in cross section so as toprovide a substantial extent of wall engagement with the cylinder andthereby ensure against accidental cocking of the piston therewithin andalso to provide a middle transverse portion 4a. In other words, thepresent form of piston consists of a middle wall 40 and the oppositecupped-out port-ions facing the two chambers 5 and 6, respectively,these cupped-out portions being of suflicient depth to serve the purposeto be explained. The wall of the piston is provided with duplicate Osealing rings 11 of elastic composition and a suitablenumber of ventsfor preventing pressure lock in the clearance between the sealing rings.

Through the centre of the piston wall .4a there extends to an equalextent upon both sides thereof the openend auxiliary cylinder 13 whichmay have screw-threaded engagement therein and which may have thescrewthreaded end heads or caps 14 and 15, respectively, with theircentral restricted apertures 14a and 15a. Within the cylinder 13 thereis the reciprocatable piston 16 with an O ring providing sealingengagement with the cylinder wall and with a coil spring 17 arrangedbetween one end of the piston and the end cap 15. That is, the spring 17is located upon the side of the piston 16 towards the gas chamber 6. Itis to be observed that the over-all length of the auxiliary pistonassembly is within the longitudinal extent of the piston 4, as indicatedin the accompanying drawing. Also, the cupped-out portions upon theopposite sides of the piston 4 serve to amplify the capacity of thechambers 5 and 6, respectively.

With the form of device shown in the present drawing, any excessivepressure in the liquid-containing chamber 5 will cause the auxiliarypiston 16 within its cylinder 13 to move towards the right, as viewed inthe present drawing, against the tension of the spring 17 and to causecompression of the gas within the right-hand end of the auxiliarycylinder and also within the main gas chamber 6 by virtue of therestricted communicating aperture 15' through the end head or cap 15.Also, the main piston 4 may be forced towards the right, as viewed inthe present drawing, by the continued excessive pressure in the chamber5. Thus, in addition to the movement of the pressure responsive mainpiston 4, there will be the response of the more sensitive auxiliarypiston or plunger 16 so as to obtain a very eflicient absorption andprevention of any shock that might otherwise result from excessivepressure within the liquid-containing chamber and thereby precludedamage incident thereto.

WhatIclaim is:

1. An accumulator comprising a cylinder, a piston reciproeatablelongitudinally within said cylinder and dividing the interior of saidcylinder into separate chainbers for a liquid and gaseous body,respectively, said chambers having inlet and outlet openings through thewall of said cylinder for passing the liquid and gaseous body,respectively, said piston being provided with a cenrespectively, saidpiston being of substantially I-form in 1 cross section so as to providecupped-out portions of subing chamber in one direction and havingaspring tending to force the same in the opposite direction.

2. An accumulator comprising a cylinder, a piston reciprocatablelongitudinally within said cylinder and dividing the interior of saidcylinder into separate chambers for a liquid and gaseous body,respectively, said chambers having inlet and outlet openingsthrough thewall of said cylinder for passing the liquid and gaseous body,respectively, an auxiliary cylinder extending coaxially through andsupported by said piston, a plunger reciprocatable within said auxiliarycylinder and exposedto the pressure within said liquid-containingchamber so as to respond thereto in one direction and having a springtending to force the same in the opposite direction, and said auxiliarycylinder having restricted openings at its two ends .in'communicationwith said chambers for the liquid and gaseous body, respectively.

3. The same structure as recited in claim 2 hereof and in which saidpiston consists of a single transverse wall with a centrally disposedaperture within which is mounted said auxiliary cylinder, said auxiliarycylinder having end closures in which said restricted openings areprovided for transmission of pressure therethrough, and the spring ofsaid plunger being in the form of a coil having bearing engagement atits outer end against the adja-- stantially equal capacity upon theopposite sides thereof, said piston being provided with a centrallydisposed auxiliary cylinder wall, an auxiliary sealed plunger mountedwithin said auxiliary cylinder wall and extending longitudinally andco-axially thereof in such manner as to be responsive to-pressure in onedirection within said liquidcontaining chamber and having a springtending to force the same in the opposite direction, and thelongitudinal extent of said auxiliary plunger being within thelongitudinal limits of said piston.

5. An accumulator comprising a cylinder, a piston reciprocatablelongitudinally withinsaid cylinder and dividing the interior of saidcylinderinto separate chambers for a liquid and gaseous body,respectively, said chambers having inlet and outlet openings through thewall of said cylinder for the liquid and gaseous body,.respectively,said piston being of substantially I-form in cross section so as toprovide cupped-out portions of substantially equal capacity uponthe-opposite sides thereof, an auxiliary cylinder extending co-axiallythrough and supported by said piston and having end closuresv each witha centrally disposed restricted aperture for transmission of pressuretherethrough, the longitudinal extent of said auxiliary cylinder andclosures therefor being within the cupped-out portions of said piston, areciprocatable plunger within said auxiliary cylinder exposed to thepressure within said liquid-containing chamber so as to respond thereto,and a coil spring arranged between said plunger and the end closureadjacent the chamber for the gaseous body.

References Cited in the file of patent UNITED STATES PATENTS Bennett etal. July 12, 1887

